The present invention generally relates to mated plug-in-socket type electrical connectors. More specifically, the present invention relates to such connectors which protect against transmission of erroneous signals caused, for instance, by static electricity.
Plug-type connectors are generally known. Known connectors have a socket plug and a pin plug which mate to form a coupled plug pair. Both the socket plug and the pin plug are generally made of insulator material. Both the pin plug and socket plug have receptacles for receiving, protecting and securing respective socket contacts. The pin plug has a set of conductive pins secured therein which are received by the corresponding socket contacts in the socket plug.
Plug-type connectors are known to have a resilient short-circuit bridge for connecting two internal connector contacts together during an uncoupled condition. To undo this short-circuit upon coupling, an associated pin plug is provided with a circuit-breaker element for each short-circuit bridge. The circuit-breaker element cancels the short-circuit between the respective socket contacts when the socket plug and pin plug are coupled. Such a plug-type connector is disclosed by German utility model 91 12 178.
Plug-type connectors are utilized, for example, in airbag systems in motor vehicles. Increasing demands on the operating reliability of such systems results in increased demands on their plug-type connectors. In addition to the conventional function of producing a releasable electrical connection, such plug-type connectors must also protect against airbag system malfunctions. For example, static electricity can create a voltage across parts of an airbag control circuit and cause an accidental deployment of an airbag. Also, spurious electromagnetic disturbances can cause such a release during operation of an automobile.
Electrostatic charges are problematic during assembly or maintenance operations on a motor vehicle. In order to avoid having individual discharge sparks result in a spurious deployment of an airbag, a power supply contact of the socket plug in an uncoupled plug-type connector is short-circuited with a low-impedance ground contact. Erroneous airbag releases are consequently prevented by diverting static electricity discharges via the ground contact.
In German utility model 91 12 178, mentioned above, a socket plug is disclosed which includes a resilient element that causes a short-circuit in an unplugged condition. This short-circuit is reliably opened, by a tongue-shaped circuit-breaker when the pin plug is coupled in the plugged condition. The circuit-breaker includes a tongue-shaped element on the pin plug configured for insertion between socket contacts and the short-circuit element when the pin plug and socket plug are coupled.
As mentioned above, spurious airbag deployment can also be caused by line-conducted, high-frequency voltages which can result from electromagnetic disturbances. Such malfunctions can occur during operation of a motor vehicle, i.e., with the plug-connector coupled, particularly within a few milliseconds of the ignition process.
To protect against airbag deployment from this sort of electrical disturbance, it is known to incorporate a second, additional plug-type connector that contains a series-connected filter component. Such a filter component has conventionally been installed during the assembly of an automobile by a soldered connection adjacent the gas-generator components of an airbag system.
Therefore, a need exists for a plug-type connector that can protect against line disturbances caused by both static charges and high-frequency noise. A further need exists for such a connector which is compact and easy to assemble.